614 REVISION OF ARAUCARIOXYLON KNOWLTON. 



24. Dadoxylon .ffigyptiacum Ung. 



Unger, Der Versteint. Wald b. Cairo, u. s. w., Sitzb. d. Mathem-Naturw. CI., 



1858, p. 228, PI. I, figs. 3-5. 

 Araucatites xEgyptiacus (Ung.) Goppert. Foss. Fl. d. Perm. Form., 1864-'65, p. 



259. 

 Araucarioxylon JEgyptiacum Kraus. See Schenk. Foss. Holz. d. Liby. Wiiste. in 



Palseoutograpbica, vol. xxx, 1883, p. 3, PI. I, figs, 1,2; n, figs. 3. 



Concentric rings indistinct; tracheitis large, thick walled, provided 

 with two to three series of small pores ; medullary rays simple, formed 

 of one to six superimposed cells. (Unger.) 



Formation doubtful, possibly Cretaceous, near Cairo, Egypt. 



25. Dadoxylon Keuperianum Endl. 



Endlicher, Syn. Conif., p. 299. Araucarites Keperianus Goppert, Monog. d. 

 Foss. Conif., p. 234. 



Concentric rings obsolete; trache'ids rather narrow, thin walled, pro- 

 vided with one to two series of small, strictly contiguous pores ; medul- 

 lary rays simple or compound, of two to fifty superimposed cells in one 

 or two series. (Goppert.) 



Permian formation, Franconia and Wiirtemberg. 



26. Dadoxylon Thuringiacum Born. Sp. 



Araucarites Thuringiacus Borneman, Org. Reste. d. Lettenk. Tburing., 1856, p. 

 61, PI. II, in, figs. 1-8. 



Concentric rings indistinct; wood cells thick walled, narrow, lumen 

 small ; walls provided with one to two series of contiguous, round or 

 slightly angular pores; medullary rays composed of a single series of 

 from one to twelve superimposed cells. 



1. Araucarioxylon Arizonicum Knowlton. 



Proc. U. S. Nat. Mus., vol. xi, 1888, pp. 1-4, PI. i. 



Araucarites Mollhausianus? Gopp., in Mollbausen's Tagebucb einer Reise vom 

 Mississippi nacb den Kiisten d. Siidsee. Leipzig, 1858, p. 492. 



Annual ring not apparent to the naked eye, but under the microscope 

 observed to be present, the yearly growth being separated by a layer 

 of two to five tangentially compressed cells; trache'ids with moderately 

 thick walls, which are provided on the radial sides with a single row of 

 large contiguous pores or rarely with two rows of alternating pores, and 

 on the tangential sides with numerous separated, perfectly round, small 

 pores; medullary numerous composed of a single series of one to twenty- 

 two short superimposed cells; resin ducts none. (Knowlton 1. c.) 



Habitat. — Triassic or lower Jurassic, near Fort Wingate, New Mex- 

 ico; Lithodendron Creek and Chalcedony Park, Arizona. 



